Cavity resonator magnetron device



Feb. 10, 1948. J. M. SPOONER CAVITY RESONATOR MAGNETRON DEVICE FiledJan. 1, 1944 INVENTOR 7 m. fPOOflE-R C (I ATTORNEY focusing efiect ofgenerated electromagneticwaves, as is well known in connection withultra high frequency electromagnetic waves.

When the magnetron is set into operation, the

slot acts as a point or slit source of electromagnetic disturbance. Theelectrostatic field vector E is at right angles to the slit.Electromagnetic field vector H is parallel to the longitudinal axis ofthe slit. The E and H vectors form a plane which provides the wave frontaccording to the classical theory. This wave is directed into thereflector and focusing portion of the envelope and directed out intospace through the lens 40.

Thus it is unnecessary to provide any coupling devices or waveguides fordirecting the generated electromagnetic waves into space. At the sametime the receiving equipment may be'well shielded from the effects ofthe pulse generated by the transmitting portion of the equipment withwhich 'my device may be used. By observing a proper ratio ofleng'th-to-flare angle, it is possible to set up interference patternswhich strongly reinforce a narrowly defined beam, while reducingspurious radiation lobes to a minimum. By disposing additional radiationsources within the structure in a suitable position, it should bepossible to vary the direction of the central lobe of the transmittedwave by varying the phase rela tionship between the various sources ofradiation, thus providing a means of scanning without mechanicalmovement of the radiating source.

While I have indicated the preferred embodiments of my invention ofwhich I am now aware and have also indicated only one specificapplication for which my invention maybe employed, it will be apparentthat my invention is by no means limited to the exact forms illustratedor the use indicated, but that many variations may be made in theparticular structure used and the purpose for which it is employedwithout departing from the scope of my invention as set forth in theappended claims.

What I claim as new is:

1. A device for use at high radio frequencies and including an elongatedenvelope having at one end an electron source and a cavity resonatorpositioned adjacent said source to be excited by electrons therefrom,said resonator having an aperture therein, said envelope having anelongated flared out portion extending from said one end and registeringwith the aperture in said resonator, said flared out portion having aconducting inner surface and providing a reflecting surface andwaveguide for electromagnetic waves generatedin said resonator, the endof said flared out portion being closed by a member permeable toelectromagnetic wave energy.

2. An electron discharge device for use at ultra high frequencies andcomprising'an elongated envelope, one end of said envelope beingprovided with a constricted portion and the remainder of said envelopebeing formed into an elongated cone-like portion closed at the outer endby a closure member permeable to electromagnetic wave energy, amagnetron electrode assemblypositioned within the constricted portion ofsaid envelope and including ar anode member forming a cavity resonatorand an electron source adjacent to said anode member for energizing thecavity resonator, said cavity resonator having an aperture opening intothe cone-like portion of said envelope, said magnetron electrodeassembly being supported from a closure member closing the'constrictedportion of said envelope, said cone-like portion of said envelope havingan inner conducting surface.

3. An electron discharge device for use at ultra high frequencies andcomprising an elongated envelope, one of said envelope being providedwith a constricted'portion and the remainder of said envelope beingformed into an elongated cone-like portion closed at the outer end. amagnetron electrode assembly within the constricted portion of saidenvelope and including an anode assembly forming a plurality of cavityresonators and an electron source adjacent to said anode assembly forenergizing said cavity resonators,

one of said cavity resonators having an aperture opening into theinterior of the cone-like portion of said envelope, said cone-likeportion of said envelope having an inner conducting surface extendingtoward the closed outer end.

4. An electron discharge device for use'at ultra high frequencies andcomprising an elongated envelope, one end of said envelopeb'eingprovided with a constricted portion and the re'mainderof saidenvelope being formed into an elongated cone-like portion closed at theouter end, a magnetron electi ode assembly within the constrictedportion of said envelope and including an anode member forming a cavityresonator and an electron source adjacent to said anode member forenergizing said cavity resonator, said cavity resonator having anaperture opening into the interior of the cone-like portion' of saidenvelope, said cone-like portion of said envelope having an innerconducting surface.

5. An electron discharge device having an en'- velope closed at one endby a cup-shaped member of conducting material, said cup-shaped membersupporting an elongated flat electrode" structure having a free endembracing an anode assembly, a cathode insulatingly supported from saidanode assembly, terminal members' extending through said envelope, leadsfor said cathode extending between said cathode andsaid terminal membersfor providing a circuit to said cathode,

the elongated flat electrode structure extending through said envelopeand having provided at the outer end thereof a radiator, said elongatedflat electrode structure having a passagewayiextending therethrough tothe exterior thereof" for exhausting said envelope, and means includedadjacent said anode assembly for providing a fixed magnetic fieldparallel to said cathode and in the space between the cathode and theanode.

6. An electron discharge device having. an envelope closed at one end bya cup-shaped member of conducting material, said cup-shaped membersupporting an elongated flat electrode structure having a free endembracing .an anode assembly comprising an apertured portion providing aplurality of anode segmentsjdefining a central space, a cathodeinsulatingly, supported from said anode assembly, terminal members.extending through said. envelope and connections extending between saidcathode. supports and said terminal members, the elongated fiatelectrode structure extending through said cupshaped member and havingprovided at the outer end thereof a radiator, and means included ad-J'acent said anode assembly for providing a fixed magnetic fieldparallel to said cathode and in the space between the cathode and theanode segments.

7. An electron discharge device having an envelope closed at one end bya cup-shaped member of conducting material, said cup-shaped membersupporting an elongated fiat electrode structure having a free endembracing an anode assembly comprising an apertured portion having aplurality of radially directed anode segments, a cathode insulatinglysupported from said anode assembly, the elongated flat electrodestructure extending through said cup-shaped member and having providedat the outer end thereof a radiator, and means included adjacent saidanode assembly for providing a fixed magnetic field parallel to saidcathode and in the space between the cathode and the anode segments.

8. An electron discharge device having an envelope provided with arestricted portion and closed by a cup-shaped member of conductingmaterial, said cup-shaped member supporting an elongated fiat electrodestructure having a free end embracing an anode assembly comprising anapertured portion including a plurality of radially extending fin-likemembers defining a plurality of cavity resonators the inner ends ofwhich provide anode segments connected by said cavity resonators, acathode insulatingly supported from said anode assembly, the elongatedflat electrode structure extending through said cup-shaped member andhaving at the outer end thereof an electro-magnetic wave radiator, theelongated flat electrode structure having a passageway extendingtherethrough for exhausting said envelope, one of said cavity resonatorsbeing provided with a slot extending through said anode assembly, saidslot opening into the space in the interior of said envelope.

9. An electron discharge device having an envelope provided with arestricted portion and closed by a cup-shaped member of conductingmaterial, said cup-shaped member supporting an elongated fiat electrodestructure having a free end embracing an anode assembly comprising anapertured portion including a, plurality of radially extending fln-likemembers, the inner ends of which provide anode segments connected bycavity resonators, a cathode having cathode leads and insulatinglysupported from said anode assembly, terminal members extending throughsaid envelope and spring connections extending between said cathodeleads and said terminal members, the elongated fiat electrode structureextending through said cup-shaped member and having at the outer endthereof an electromagnetic wave radiator, and having a passagewayextending therethrough for exhausting said envelope, and means includedadjacent said anode assembly providing a fixed magnetic field parallelto said cathode and in the space between the cathode and the anodesegments, one of said cavity resonators being provided with a slotextending through said anode assembly and opening into the space in theinterior of said envelope.

10. An electron discharge device having an elongated envelope closed atone end by a cupshaped member of conductive material, said cupshapedmember supporting an electrode structure within said envelope, saidelectrode structure including a cathode, terminal members extendingthrough said envelope and spring-like conductors having one endconnected to said cathode and the other end free and extending betweensaid cathode and the terminal members in said envelope, the free ends ofsaid spring like conductors frictionally engaging said terminal memberswhereby contact is made between said spring-like conductors and saidterminal members when said cup-shaped member is sealed to the end ofsaid envelope.

11. An electron discharge device having an elongated envelope having atone end a restricted portion and an electrode assembly mounted in saidrestricted portion and comprising a magnetron electrode assembly, saidassembly including an anode member provided with a cavity resonator andan electron source associated with said anode member for supplyingelectrons for energizing the cavity resonator, said envelope having anelongated cone-like portion extending from said restricted portion, saidcavity resonator having an aperture opening into said conelike portionof said envelope, said magnetron electrode assembly being supported froma closure member closing the restricted portion of the envelope, theaxis of said electrode assembly being transverse to the longitudinalaxis of said envelope, said cone-like portion of said envelope having aninner conductive surface.

JOHN M. SPOONER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,223,082 Van Mierlo Nov. 26,1940 2,372,193 Fisk Mar. 27, 1945 2,300,052 Lindenblad Oct. 27, 19422,247,077 Blewett et al June 24, 1941 2,375,223 Hansen et al May 8, 19452,153,728 Southworth Apr. 11, 1939 2,283,935 King May 26, 1942 2,263,248Roberts Nov. 18, 1941 2,128,233 Dallenbach Aug. 30, 1938 2,329,777Nergaard Sept. 21, 1943 Certificate of Correction Patent No. 2,435,804February 10, 1948 JOHN M. SPOONER It is hereby certified that errorappears in the printed specification of the above numbered patentrequiring correction as follows:

Column 4, line 14, after the Word one insert end;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 11th day of July, A. D. 1950.

[sun] THOMAS F. MURPHY,

Assistant C'ommz'ssz'oner of Patents.

Disclaimer 2,435,804.J0hn M. Spooner, Manheim Township, Lancaster'County, Pa. CAVI'FY RESONATOR MAGNE'I'RON DEVICE. Patent dated Feb. 10,1948. D1sclaimer filed Apr. 12, 1950, by the assignee, Radio Corporationof Amenca. Hereby enters this disclaimer to claims 1 and 4 of saidpatent.

[Oflicial Gazette May 16, 1950.]

